/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.optimize.info;

import proguard.classfile.*;
import proguard.classfile.visitor.ClassVisitor;

/**
 * This ClassVisitor delegates its visits to one of two other given ClassVisitor instances, depending on whether the
 * classes are marked to be escaping or not.
 *
 * @see EscapingClassMarker
 *
 * @author Eric Lafortune
 */
public class EscapingClassFilter implements ClassVisitor {
    private final ClassVisitor escapingClassVisitor;
    private final ClassVisitor otherClassVisitor;

    /**
     * Creates a new EscapingClassFilter.
     * 
     * @param escapingClassVisitor the class visitor to which visits to classes that are marked to be escaping will be
     *        delegated.
     */
    public EscapingClassFilter(ClassVisitor escapingClassVisitor) {
        this(escapingClassVisitor, null);
    }

    /**
     * Creates a new EscapingClassFilter.
     * 
     * @param escapingClassVisitor the class visitor to which visits to classes that are marked to be escaping will be
     *        delegated.
     * @param otherClassVisitor the class visitor to which visits to classes that are not marked to be escaping will be
     *        delegated.
     */
    public EscapingClassFilter(ClassVisitor escapingClassVisitor, ClassVisitor otherClassVisitor) {
        this.escapingClassVisitor = escapingClassVisitor;
        this.otherClassVisitor = otherClassVisitor;
    }

    // Implementations for ClassVisitor.

    public void visitLibraryClass(LibraryClass libraryClass) {
        // Is the class marked to be escaping?
        ClassVisitor classVisitor =
            EscapingClassMarker.isClassEscaping(libraryClass) ? escapingClassVisitor : otherClassVisitor;

        if (classVisitor != null) {
            classVisitor.visitLibraryClass(libraryClass);
        }
    }

    public void visitProgramClass(ProgramClass programClass) {
        // Is the class marked to be escaping?
        ClassVisitor classVisitor =
            EscapingClassMarker.isClassEscaping(programClass) ? escapingClassVisitor : otherClassVisitor;

        if (classVisitor != null) {
            classVisitor.visitProgramClass(programClass);
        }
    }
}
